I was on the Glory in 2007. It's a huge ship and might take you a few days to learn your way around. Get one of the little pocket maps they have. There is a Deli (window) on the Lido deck that has great sandwiches, also there is an oriental (window) on the Lido deck, but it seemed to always be closed when we walked by. If you eat at the buffet and it is crowded, go upstairs to where the fish and chips place is, there seemed to always be tables up there.
I don't know of any secret or hidden places, the balcony the another poster was talking about is nice, but if you are short, like me, you can't see over the railing. We were out there the day we got ont he ship and I had to stretch to see below.
Here is link to my photos of the ship. Enjoy your cruise.